For a keyboard used in an electronic device such as a personal computer (PC), there is widely used a configuration including a base plate, a membrane sheet provided on the upper surface of the base plate, and a set of key switches disposed so as to be vertically movable on the upper surface side of the base plate.
In a keyboard, a wider key top than the key tops of other key switches is used for a space key or a shift key. This kind of wide key top may be twisted or inclined when the key top is depressed. The key top unstably moves vertically, which may lead to not only a deterioration of the operability or operation quality, but also a failure in detection of the depressing operation.
In order to overcome the above-mentioned problem, a stabilizer member, which is a metal rod-like member, can be provided between a space key and a base plate to stabilize the vertical movement of the key top. In a key switch provided with a metal stabilizer member, normally a bearing formed by cutting and raising a part of a metal base plate rotatably supports an end of the stabilizer member. In this situation, a gap is provided for a design to absorb a manufacturing tolerance between the stabilizer member and the bearing, and therefore a depressing operation of a key top generates contact noise due to contact of metals or causes wobbling between the bearing and the stabilizer member.
In order to prevent an occurrence of metallic sound and wobbling, grease can be applied to an area between the bearing and the stabilizer member. In the case of using grease, however, it requires a time-consuming grease coating operation and thus reduces manufacturing efficiency. Moreover, if the grease adheres to a worker's hand or to other components, a wiping work or the like therefor is required, by which the manufacturing efficiency is further reduced. In addition, this problem may occur similarly in devices other than the key switch of the keyboard device, such as, for example, various push-button type switch devices provided in an electronic device or the like.
Consequently, it would be desirable to provide an improved switch device capable of preventing an occurrence of contact noise and wobbling of a stabilizer member to a bearing.